Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in PYTHON3):

Solution:
from collections import Counter
s = input()
ans = 0
count = Counter(s)
for i,j in count.items():
      if i.isalpha():
            ans+=1
print(ans)










'''
for i in range(int(input())):
    n = int(input())
    s = input()
    s = list(s)
    a = True
    b = True
    for i in range(n):
        if s[i]=='>':
            a = False
        if s[i]=='<':
            b = False
    if a or b:
        print(n)
    else:
        count = 0
        for i in range(n):
            if s[i]=='-' or s[(i+1)%n]=='-':
                count+=1
        print(count)
        
'''







'''
n,k = map(int,input().split())
arr = list(map(int,input().split()))
q = list(map(int,input().split()))


for i in range(k):
    l = 0
    r = n-1
    while l<=r:
        mid = l + (r-l)//2
        if arr[mid] == q[i]:
            print('YES')
            break
        elif arr[mid] < q[i]:
            l = mid + 1
        else:
            r = mid-1
    else:
        print('NO')


for i in range(k):
    l = -1
    r = n
    while r>l+1:
        mid = l + (r-l)//2
        if arr[mid]<=q[i]:
            l = mid
        else:
            r = mid
    if l==-1:
        print(0)
    else:
        print(l+1)
        

for i in range(k):
    l = -1
    r = n
    while r>l+1:
        mid = l+(r-l)//2
        if arr[mid]<q[i]:
            l=mid
        else:
            r = mid
    if r==n:
        print(n+1)
    else:
        print(r+1)  


n = int(input())
arr  = list(map(int,input().split()))
q = int(input())
ans = [0]*(q)
for i in range(q):
    a,b = map(int,input().split())
    arr = sorted(arr)
    l = -1 
    r = n
    while r>l+1:
        mid = l + (r-l)//2
        if arr[mid]<a:
            l = mid
        else:
            r = mid
    ans1 = r+1
    l = -1
    r = n
    while r>l+1:
        mid = l + (r-l)//2
        if arr[mid]<=b:
            l = mid
        else:
            r = mid
    ans2 = l+1
    ans[i] = ans2-ans1+1
print(" ".join(map(str,ans)))

w,h,n = map(int,input().split())
def good(w,h,n,x):
    return (x//w)*(x//h)>=n

l = 0 
r = 1
while not good(w,h,n,r):
    r*=2
while r>l+1:
    mid = l+(r-l)//2
    if good(w,h,n,mid):
        r= mid
    else:
        l = mid

print(r)

n,k = map(int,input().split())
arr = []
for i in range(n):
    arr.append(int(input()))
def good(arr,x,k):
    s = 0
    for i in range(n):
        s += arr[i]//x

    return s>=k

l = 0  #l is good 
r = 1e8  #r is bad
for i in range(100):
    mid = l+(r-l)/2
    if good(arr,mid,k):
        l = mid
    else:
        r = mid

print(l)

s = input()
s = s.split(' ')
d = dict()
for i in s:
    if i in d:
        d[i] +=1
    else:
        d[i]=1
ans = []
for i,j in d.items():
    if j>1 and i.isalpha():
        ans.append([i,j])
print(" ".join(map(str, ans)))

try:
    a,b = map(int,input().split())
    c = a-b
    c = str(c)
    
    for i in range(1,10):
        if i!=c[-1]:
            c[-1] = i
            break
    
    print(c)
except:
    pass
'''